4
6. Repeat the operations mentioned above (4 and 5), to adjust the object position on the CRT,
until the object moving is restricted within 6 mm.
When necessary, perform the operation mentioned above,
②
.
Note: The completed axis adjustments prevent the conspicuous moving of the object image,
even if the PROBE CURRENT knob is rotated greatly.
Notice: When the current is unstable, the unstable current emission always induces the
deviation of the optical axis. To solve the deviation, the axis adjustments should
be performed repeatedly.
④
The adjustment of the beam axis (the alternative method)
1. Press the
EOS
ー
MODE
button once, to select the
SEM1
mode.
Minimize the magnification, using the
MAGNIFICATION
knob.
2. Set the
CL COARSE
value (
EOS
menu,
EOS-1
,
OPTICS
) to
7
, using the
PROBE
CURRENT
knob.
Maximize the image brightness, using the
GUN ALIGNMENT (X, Y)
knobs.
3. Decrease the
CL COARSE
value, and maximize the image brightness, using the
GUN
ALIGNMENT(X, Y)
.
Finally, set the
CL COARSE
value to
1
, to attain the maximum image brightness.
4. Set the
CL COARSE
value to
7
again.
Notice: When the current is unstable, the unstable current emission always induces the
deviation of the optical axis. To solve the deviation, the axis adjustments should
be performed repeatedly.
⑤
The
CL
correcting of astigmatism
1. Display the
EOS-1
at the right side of the CRT, and change the
STIGMA
from the
OL
to the
CL
.
2. Display the
EOS-2
, and change the
EOS MODE
from the
SEM
to the
ALP
.
3. Set the
SCAN SPEED
value to
2
.
4. To form the complete circle of the beam spot on the CRT, adjust the beam spot shape, using
the
STIGMATOR (X, Y)
knob.
5. Change the
EOS MODE
of the
EOS-2
from the
ALP
to the
SEM
.
6. Display the
EOS-1
, and change the
STIGMA
from the
OL
to the
CL
.
Notice: For the observation by high magnification, perform the CL astigmatism correction, when
